In the process automation industry, object linking and embedding for process control (OPC) provides a standard for communicating with field devices. This standard allows for accessing process data, alarms, events, and historical process data. In a typical monitoring and control network, one or more servers are equipped with the OPC Server application which receives field device data and stores the data in volatile memory.
Function Blocks implemented in the field device controller, control the operation of the field devices and overall system, for example, data is constantly being updated through polling functions initiated by the process control server. A client computer is typically equipped with a Human Machine Interface (HMI) application that is used to visualize and interact with the field devices using symbolic images and standard windows widgets (e.g. listbox, textbox, radio button, checkbox). The HMI contains programs/drivers capable of communicating through function blocks with any process control server accessible locally on the same computer or from the network.
Parameters used to regulate the process control system may need to be altered for specific conditions that may require human observation. However, changes to these parameters may have detrimental effects if the entered parameters are outside acceptable ranges or not carefully considered. Accordingly, an efficient device, system and method are needed for allowing parameters to be altered safely without error by one or more operators. In addition, a device, system and method may need to provide for using restart parameters during warm start or testing other than setting back to the safety cold start parameters.